The Britannica is the oldest English-language encyclopaedia still in print. It was first published between 1768 and 1771 in Edinburgh, Scotland and quickly grew in popularity and size, with its third edition in 1801 reaching over 21 volumes. Its rising stature helped in recruiting eminent contributors, and the 9th edition (1875–1889) and the 11th edition (1911) are regarded as landmark encyclopaedias for scholarship and literary style. Beginning with the 11th edition, the Britannica gradually shortened and simplified its articles in order to broaden its North American market. In 1933, the Britannica became the first encyclopaedia to adopt a "continuous revision" policy, in which the encyclopaedia is continually reprinted and every article is updated on a regular schedule.

The current 15th edition has a unique three-part structure: a 12-volume Micropædia of short articles (generally having fewer than 750 words), a 17-volume Macropædia of long articles (having from two to 310 pages) and a single Propædia volume intended to give a hierarchical outline of human knowledge. The Micropædia is meant for quick fact-checking and as a guide to the Macropædia; readers are advised to study the Propædia outline to understand a subject's context and to find other, more detailed articles. The size of the Britannica has remained roughly constant over the past 70 years, with about 40 million words on half a million topics. Although publication has been based in the United States since 1901, the Britannica has maintained its traditional British spelling.

Over the course of its history, the Britannica has had difficulty remaining profitable—a problem faced by many encyclopaedias. Some articles in certain earlier editions of the Britannica have been criticised for inaccuracy, bias or unqualified contributors. The accuracy in parts of the present edition have likewise been questioned, although such criticisms have been challenged by the Britannica's management. Despite these criticisms, the Britannica retains its reputation as a reliable research tool.

Editions

The Britannica has been issued in 15 official editions, with multi-volume supplements to the 3rd and 5th editions (see the Table below). Strictly speaking, the 10th edition was only a supplement to the 9th edition, just as the 12th and 13th editions were supplements to the 11th edition. The 15th edition underwent a massive re-organisation in 1985, but the updated, current version is still known as the 15th edition.

Throughout its history, the Britannica has had two aims: to be an excellent reference book and to provide educational material for those who wish to study. In 1974, the 15th edition adopted a third goal: to systematise all of human knowledge. The history of the Britannica can be divided into five main eras, punctuated by major changes in management or re-organisation of the encyclopaedia.

First era

In the first era (1st–6th editions, 1768–1826), the Britannica was managed by its original founders, Colin Macfarquhar and Andrew Bell, and by their friends and relations, such as Thomas Bonar, George Gleig and Archibald Constable. The Britannica was first published between 1768 and 1771 in Edinburgh as the Encyclopædia Britannica, or, A dictionary of arts and sciences, compiled upon a new plan. It was conceived as a conservative reaction to the provocative French Encyclopédie of Denis Diderot (published 1751–1766), which in turn had been inspired by the earlier Chambers Cyclopaedia. The Britannica was primarily a Scottish enterprise, as symbolised by its thistle logo, the floral emblem of Scotland. The founding of the encyclopaedia is one of the most famous and enduring legacies of the Scottish Enlightenment. In this era, the Britannica moved from being a three-volume set (1st edition) compiled by one young editor—William Smellie—to a 20-volume set written by numerous authorities. Although several other encyclopaedias competed with the Britannica, such as Rees's Cyclopaedia and Coleridge'sEncyclopaedia Metropolitana, these competitors either went bankrupt or were left unfinished due to disagreements among their editors. By the close of this era, the Britannica had developed a network of illustrious contributors, primarily through personal friendships with the editors, most notably Constable and Gleig.

Second era

During the second era (7th–9th editions, 1827–1901), the Britannica was managed by the Edinburgh publishing firm, A & C Black. Although some contributors were again recruited through personal friendships of the chief editors, most notably Macvey Napier, others were attracted by the Britannica's ever-improving reputation. The contributors often came from other countries and included some of the world's most respected authorities in their fields. A general index of all articles was included for the first time in the 7th edition, a practice that was maintained until 1974. The first English-born editor-in-chief was Thomas Spencer Baynes, who oversaw the production of the famous 9th edition; dubbed the "Scholar's Edition", the 9th is often considered to be the most scholarly Britannica ever produced. However, by the close of the 19th century, the 9th edition was outdated and the Britannica faced significant financial difficulties.

Third era

In the third era (10th–14th editions, 1901–1973), the Britannica was managed by American businessmen, who introduced aggressive marketing practices, such as direct marketing and door-to-door sales, to increase profits. The American owners also gradually simplified the Britannica's articles, making them less scholarly but more intelligible to a mass market. The 10th edition was a rapidly produced supplement to the 9th edition, but the 11th edition is still praised for its excellence; its owner, Horace Hooper, lavished enormous effort on its perfection. When Hooper fell into financial difficulties, the Britannica was managed by Sears Roebuck for roughly 18 years (1920–1923, 1928–1943). In 1932, the vice-president of Sears, Elkan Harrison Powell, assumed the presidency of the Britannica; in 1936, he began the policy of continuous revision (still practiced today), in which every article is checked and possibly revised at least twice a decade. This was a major departure from earlier practice, in which the articles were not changed until a new edition was produced, at roughly 25-year intervals, with some articles being carried over unchanged from earlier editions. Powell aggressively developed new educational products that built upon the Britannica's reputation. In 1943, ownership passed from Sears Roebuck to William Benton, who managed the Britannica until his death in 1973. Benton also set up the Benton Foundation, which managed the Britannica until 1996. In 1968, near the end of this era, the Britannica celebrated its bicentennial.

Fourth era

In the fourth era (15th edition, 1974–1994), the Britannica introduced its 15th edition, which was re-organised into three parts: the Micropædia, the Macropædia and the Propædia. Under the influence of Mortimer J. Adler (member of the Board of Editors of Encyclopædia Britannica since its inception in 1949, and its chair from 1974; director of editorial planning for the fifteenth edition of Britannica from 1965), the Britannica sought not only to be a good reference work and educational tool, but also to systematise all of human knowledge. The absence of a separate index and the grouping of articles into two parallel encyclopaedias (the Micro- and Macropædia) provoked a "firestorm of criticism" of the initial 15th edition. In response, the 15th edition was completely re-organised and indexed for a re-release in 1985. This second version of the 15th edition continues to be published and revised; the latest version is the 2007 print version. The official title of the 15th edition is the New Encyclopædia Britannica, although it has also been promoted as Britannica 3.

Dedications

The Britannica was dedicated to the reigning British monarch from 1788 to 1901 and then, upon its sale to an American partnership, to both the British monarch and the President of the United States. Thus, the 11th edition is "dedicated by Permission to His Majesty George the Fifth, King of Great Britain and Ireland and of the British Dominions beyond the Seas, Emperor of India, and to William Howard Taft, President of the United States of America." The order of the two dedications has changed with the relative power of the United States and Britain, and with the relative sales of the Britannica in these countries; the 1954 version of the 14th edition is "Dedicated by Permission to the Heads of the Two English-Speaking Peoples, Dwight David Eisenhower, President of the United States of America, and Her Majesty, Queen Elizabeth the Second." Consistent with this tradition, the 2007 version of the current 15th edition is "dedicated by permission to the current President of the United States of America, George W. Bush, and Her Majesty, Queen Elizabeth II."

The Britannica has a popular reputation for summarising all of human knowledge. To further their education, many have devoted themselves to reading the entire Britannica, taking anywhere from three to 22 years to do so. When Fat'h Ali became the Shah of Persia in 1797, he was given a complete set of the Britannica's 3rd edition, which he read completely; after this feat, he extended his royal title to include "Most Formidable Lord and Master of the Encyclopædia Britannica." Writer George Bernard Shaw claimed to have read the complete 9th edition—except for the science articles—and Richard Evelyn Byrd took the Britannica as reading material for his five-month stay at the South Pole in 1934, while Philip Beaver read it during a sailing expedition. More recently, A.J. Jacobs, an editor at Esquire magazine, read the entire 2002 version of the 15th edition, describing his experiences in the well-received 2004 book, The Know-It-All: One Man's Humble Quest to Become the Smartest Person in the World. Only two people are known to have read two independent editions: the author C. S. Forester and Amos Urban Shirk, an American businessman, who read the 11th and 14th editions, devoting roughly three hours per night for four and a half years to read the 11th. Several editors-in-chief of the Britannica are likely to have read their editions completely, such as William Smellie (1st edition), William Robertson Smith (9th edition), and Walter Yust (14th edition).

Awards

The Britannica continues to win awards. The online Britannica won the 2005 Codie award for "Best Online Consumer Information Service"; the Codie awards are granted yearly by the Software and Information Industry Association to recognise the best products among categories of software. In 2006, the Britannica was again a finalist. Similarly, the CD/DVD-ROM version of the Britannica received the 2004 Distinguished Achievement Award from the Association of Educational Publishers, and Codie awards in 2000, 2001 and 2002.

Coverage of topics

As a general encyclopaedia, the Britannica seeks to describe as wide a range of topics as possible. The topics are chosen in part by reference to the Propædia "Outline of Knowledge". The bulk of the Britannica is devoted to geography (26% of the Macropædia), biography (14%), biology and medicine (11%), literature (7%), physics and astronomy (6%), religion (5%), art (4%), Western philosophy (4%), and law (3%). A complementary study of the Micropædia found that geography accounted for 25% of articles, science 18%, social sciences 17%, biography 17%, and all other humanities 25%. Writing in 1992, one reviewer judged that the "range, depth, and catholicity of coverage [of the Britannica] are unsurpassed by any other general encyclopedia.

The Britannica does not cover similar topics in equivalent detail; for example, the whole of Buddhism and most other religions is covered in a single Macropædia article, whereas 14 articles are devoted to Christianity, comprising nearly half of all religion articles. However, the Britannica has been lauded as the least biased of general encyclopedias marketed to Western readers and praised for its biographies of important women of all eras.

It can be stated without fear of contradiction that the 15th edition of the Britannica accords non-Western cultural, social, and scientific developments more notice than any general English-language encyclopedia currently on the market.|20|20|Kenneth Kister|in Kister's Best Encyclopedias (1994)

Criticisms

The Britannica has also received criticism, especially as its editions become outdated. It is expensive to produce a completely new edition of the Britannica, and its editors generally delay this for as long as fiscally sensible (usually about 25 years). For example, despite the policy of continuous revision, the 14th edition had become significantly outdated after 35 years (1929–1964). When American physicist Harvey Einbinder detailed its failings in his 1964 book, The Myth of the Britannica, the encyclopaedia was provoked to produce the 15th edition, which required 10 years of work. It is still difficult to keep the Britannica current; one recent critic writes, "it is not difficult to find articles that are out-of-date or in need of revision," noting that the longer Macropædia articles are more likely to be outdated than the shorter Micropædia articles. Information in the Micropædia is sometimes inconsistent with the corresponding Macropædia article(s), mainly because of the failure to update one or the other. The bibliographies of the Macropædia articles have been criticised for being more out-of-date than the articles themselves.

Historically, the Britannica's authors have included eminent authorities, such as Albert Einstein, Marie Curie and Leon Trotsky. However, some of its contributors have been criticised for their lack of expertise:

With a temerity almost appalling, [the Britannica contributor, Mr. Philips] ranges over nearly the whole field of European history, political, social, ecclesiastical… The grievance is that [this work] lacks authority. This, too—this reliance on editorial energy instead of on ripe special learning—may, alas, be also counted an "Americanizing": for certainly nothing has so cheapened the scholarship of our American encyclopaedias.|20px|20px|Prof. George L. Burr|in the American Historical Review (1911)

Bias

Various authorities ranging from Virginia Woolf to academic professors criticised the 11th edition Britannica for having bourgeois and old-fashioned opinions on art, literature and social sciences. For example, it was faulted for neglecting the work of Sigmund Freud. A contemporary Cornell professor, Edward B. Titchener, wrote in 1912, "the new Britannica does not reproduce the psychological atmosphere of its day and generation… Despite the halo of authority, and despite the scrutiny of the staff, the great bulk of the secondary articles in general psychology … are not adapted to the requirements of the intelligent reader.

Editorial choices

The Britannica is occasionally criticised for its editorial choices. Given its roughly constant size, the encyclopaedia has needed to reduce or eliminate some topics to accommodate others, resulting in some controversial decisions. The initial 15th edition (1974–1985) was faulted for having drastically reduced or eliminated its coverage of children's literature, military decorations, and the French poet Joachim du Bellay; editorial mistakes were also alleged, such as an inconsistent sorting of Japanese biographies. Its elimination of the index was condemned, as was the apparently arbitrary division of articles into the Micropædia and Macropædia. Summing up, one critic called the initial 15th edition a "qualified failure…[that] cares more for juggling its format than for preserving information." More recently, reviewers from the American Library Association were surprised to find that most educational articles had been eliminated from the 1992 Macropædia, along with the article on psychology.

Britannica-appointed contributors are occasionally mistaken or unscientific. A notorious instance from the Britannica's early years is the rejection of Newtonian gravity by George Gleig, the chief editor of the 3rd edition (1788–1797), who wrote that gravity was caused by the classical element of fire. However, the Britannica has also staunchly defended a scientific approach to emotional topics, as it did with William Robertson Smith's articles on religion in the 9th edition, particularly his article stating that the Bible was not historically accurate (1875).

Racism and sexism in prior editions

By modern standards, past editions of the Britannica have contained articles marred by racism and sexism. The 11th edition characterises the Ku Klux Klan as protecting the white race and restoring order to the American South after the American Civil War, citing the need to "control the negro", to "prevent any intermingling of the races" and "the frequent occurrence of the crime of rape by negro men upon white women. Similarly, the article on Civilization argues for eugenics, stating that it is irrational to "propagate low orders of intelligence, to feed the ranks of paupers, defectives and criminals … which to-day constitute so threatening an obstacle to racial progress. The 11th edition has no biography of Marie Curie, despite her winning of the Nobel Prize in Physics in 1903 and the Nobel Prize in Chemistry in 1911, although she is mentioned briefly under the biography of her husband Pierre Curie. The Britannica employed a large female editorial staff that wrote hundreds of articles for which they were not given credit.

Inaccuracy

In 1912 mathematician L. C. Karpinski criticised the Encyclopædia Britannica Eleventh Edition for its many inaccuracies in the articles on the history of mathematics, none of which had been written by specialists in the field. In 1917, art critic Willard Huntington Wright published a book, Misinforming a Nation, that highlighted inaccuracies and English biases of the Eleventh Edition, particularly in the humanities articles. Many of Wright's criticisms were addressed in later editions of the Britannica. However, his book was denounced as a polemic by some contemporary reviewers; for example, the New York Times wrote that a "spiteful and shallow temper…pervades the book," while The New Republic opined, "it is unfortunate for Mr. Wright's remorseless purpose that he has proceeded in an unscientific spirit and given so little objective justification of his criticism." Another critic, English writer and former priest Joseph McCabe, claimed that after the 11th edition the Britannica was censored under pressure from the Roman Catholic Church in his book, Lies And Fallacies Of The Encyclopedia Britannica (1947).

The Britannica has always conceded that errors are inevitable in an encyclopaedia. Speaking of the 3rd edition (1788–1797), its chief editor George Gleig wrote that "perfection seems to be incompatible with the nature of works constructed on such a plan, and embracing such a variety of subjects." More recently (March 2006), the Britannica wrote that "we in no way mean to imply that Britannica is error-free; we have never made such a claim."
The sentiment is expressed by its original editor, William Smellie.

With regard to errors in general, whether falling under the denomination of mental, typographical or accidental, we are conscious of being able to point out a greater number than any critic whatever. Men who are acquainted with the innumerable difficulties of attending the execution of a work of such an extensive nature will make proper allowances. To these we appeal, and shall rest satisfied with the judgment they pronounce.|20px|20px|William Smellie|in the Preface to the 1st edition of the Encyclopædia Britannica to the 1st edition of the Encyclopædia Britannica

Present status

2007 print version

Since 1985, the Britannica has had four parts: the Micropædia, the Macropædia, the Propædia, and a two-volume index. The Britannica's articles are found in the Micro- and Macropædia, which encompass 12 and 17 volumes, respectively, each volume having roughly one thousand pages. The 2007 Macropædia has 699 in-depth articles, ranging in length from 2 to 310 pages and having references and named contributors. In contrast, the 2007 Micropædia has roughly 65,000 articles, the vast majority (about 97%) of which contain fewer than 750 words, no references, and no named contributors. The Micropædia articles are intended for quick fact-checking and to help in finding more thorough information in the Macropædia. The Macropædia articles are meant both as authoritative, well-written articles on their subjects and as storehouses of information not covered elsewhere. The longest article (310 pages) is on the United States, and resulted from the merger of the articles on the individual states.

Information can be found in the Britannica by following the cross-references in the Micropædia and Macropædia; however, these are sparse, averaging one cross-reference per page. Hence, readers are recommended to consult instead the alphabetical index or the Propædia, which organises the Britannica's contents by topic.

The core of the Propædia is its "Outline of Knowledge," which aims to provide a logical framework for all human knowledge. Accordingly, the Outline is consulted by the Britannica's editors to decide which articles should be included in the Micro- and Macropædia. The Outline is also intended to be a study guide, to put subjects in their proper perspective, and to suggest a series of Britannica articles for the student wishing to learn a topic in depth. However, libraries have found that it is scarcely used, and reviewers have recommended that it be dropped from the encyclopedia. The Propædia also has color transparencies of human anatomy and several appendices listing the staff members, advisors, and contributors to all three parts of the Britannica.

Taken together, the Micropædia and Macropædia comprise roughly 40 million words and 24,000 images. The two-volume index has 2,350 pages, listing the 228,274 topics covered in the Britannica, together with 474,675 subentries under those topics. The Britannica generally prefers British spelling over American; for example, it uses colour (not color), centre (not center), and encyclopaedia (not encyclopedia). However, there are exceptions to this rule, such as defense rather than defence. Common alternative spellings are provided with cross-references such as "Color: see Colour."

Since 1936, the articles of the Britannica have been revised on a regular schedule, with at least 10% of them considered for revision each year. According to one Britannica web-site, 46% of its articles were revised over the past three years; however, according to another Britannica web-site, only 35% of the articles were revised.

The alphabetisation of articles in the Micropædia and Macropædia follows strict rules. Diacritical marks and non-English letters are ignored, while numerical entries such as "1812, War of" are alphabetised as if the number had been written out ("Eighteen-twelve, War of"). Articles with identical names are ordered first by persons, then by places, then by things. Rulers with identical names are organised first alphabetically by country and then by chronology; thus, Charles III of France precedes Charles I of England, listed in Britannica as the ruler of Great Britain and Ireland. (That is, they are alphabetised as if their titles were "Charles, France, 3" and "Charles, Great Britain and Ireland, 1".) Similarly, places that share names are organised alphabetically by country, then by ever-smaller political divisions.

Related printed material

There have been and are several abbreviated Britannica encyclopedias. The single-volume Britannica Concise Encyclopædia has 28,000 short articles condensing the larger 32-volume Britannica. Compton's by Britannica, first published in 2007, incorporating the former Compton's Encyclopedia, is aimed at adolescents ages 10–17 and consists of 26 volumes and 11,000 pages. A Children's Britannica was published by the company's London office in 1960; this was edited by John Armitage and dedicated to His Royal Highness the Prince of Wales; contributors were almost all British, and editorial consultants were "The Headmaster, Staff and Children of the William Austin Primary School, Luton, Bedfordshire". Other products include My First Britannica, aimed at children ages six to twelve, and the Britannica Discovery Library, written for children ages three to six (issued 1974 to 1991). Since 1938, Encyclopædia Britannica, Inc. has published annually a Book of the Year covering the past year's events, which is available online back to the 1994 edition (covering the events of 1993). The company also publishes several specialized reference works, such as Shakespeare: The Essential Guide to the Life and Works of the Bard (Wiley, 2006).

Optical disc and online and mobile versions

The Britannica Ultimate Reference Suite 2006 DVD contains over 55 million words and just over 100,000 articles. This includes 73,645 regular Britannica articles, with the remainder drawn from the Britannica Student Encyclopædia, the Britannica Elementary Encyclopædia and the Britannica Book of the Year (1993–2004), plus a few "classic" articles from early editions of the encyclopaedia. The package includes a range of supplementary content including maps, videos, sound clips, animations and web links. It also offers study tools and dictionary and thesaurus entries from Merriam-Webster.

Encyclopædia Britannica Online is a Web site with more than 120,000 articles and is updated regularly. It has daily features, updates and links to news reports from The New York Times and the BBC. Subscriptions are available on a yearly, monthly or weekly basis. Special subscription plans are offered to schools, colleges and libraries; such institutional subscribers constitute an important part of Britannica's business. Articles may be accessed online for free, but only a few opening lines of text are displayed. Beginning in early 2007, the Britannica made articles freely available if they are linked to from an external site; such external links often improve an article's rankings in search engine results.

On 20 February 2007, Encyclopædia Britannica, Inc. announced that it was working with mobile phone search company AskMeNow to launch a mobile encyclopedia. Users will be able to send a question via text message, and AskMeNow will search Britannica's 28,000-article concise encyclopedia to return an answer to the query. Daily topical features sent directly to users' mobile phones are also planned.

On 3 June 2008, an initiative to facilitate collaboration between online expert and amateur scholarly contributors for Britannica's on-line content (in the spirit of a wiki), with editorial oversight from Britannica staff, was announced.

Personnel and management

Contributors

The 2007 print version of the Britannica boasts 4,411 contributors, many eminent in their fields, such as Nobel Laureate economist Milton Friedman, astronomer Carl Sagan, and surgeon Michael DeBakey. Roughly a quarter of the contributors are deceased, some as long ago as 1947 (Alfred North Whitehead), while another quarter are retired or emeritus. Most (approximately 98%) contribute to only a single article; however, 64 contributed to three articles, 23 contributed to four articles, 10 contributed to five articles, and 8 contributed to more than five articles. An exceptionally prolific contributor is Dr. Christine Sutton of the University of Oxford, who contributed 24 articles on particle physics.

The Britannica maintains an editorial staff of five Senior Editors and nine Associate Editors, supervised by Dale Hoiberg and four others. The editorial staff help in authoring the articles of the Micropædia and some sections of the Macropædia.

Editorial advisors

The Britannica has an Editorial Board of Advisors, which includes 12 distinguished scholars:

In 2003, former management consultant Jorge Aguilar-Cauz was appointed President of Encyclopædia Britannica, Inc. Cauz is the senior executive and reports directly to the Britannica's Board of Directors. Cauz has been pursuing alliances with other companies and extending the Britannica brand to new educational and reference products, continuing the strategy pioneered by former CEO Elkan Harrison Powell in the mid-1930s.

Under Safra's ownership, the company has experienced financial difficulties, and has responded by reducing the price of its products and implementing drastic cost cuts. According to a 2003 report in the New York Post, the Britannica management has eliminated employee 401(k) accounts and encouraged the use of free images. These changes have had negative impacts, as freelance contributors have waited up to six months for checks and the Britannica staff have gone years without pay rises.

Encyclopædia Britannica, Inc. now owns registered trademarks on the words Britannica, Encyclopædia Britannica, Macropædia, Micropædia, and Propædia, as well as on its thistle logo. It has exercised its trademark rights as recently as 2005.

Competition

As the Britannica is a general encyclopaedia, it does not seek to compete with specialised encyclopaedias such as the Encyclopaedia of Mathematics or the Dictionary of the Middle Ages, which can devote much more space to their chosen topics. In its first years, the Britannica's main competitor was the general encyclopaedia of Ephraim Chambers and, soon thereafter, Rees's Cyclopaedia and Coleridge'sEncyclopaedia Metropolitana. In the 20th century, successful competitors included Collier's Encyclopedia, the Encyclopedia Americana, and the World Book Encyclopedia. Each of these encyclopaedias has qualities that make it outstanding, such as exceptionally clear writing or superb illustrations. Nevertheless, from the 9th edition onwards, the Britannica was widely considered to have the greatest authority of any general English language encyclopaedia, especially because of its broad coverage and eminent authors. However, the print version of the Britannica is significantly more expensive than its competitors.

Since the early 1990s, the Britannica has faced new challenges from digital information sources. The Internet, facilitated by the development of search engines, has grown into a common source of information for many people, and provides easy access to reliable original sources and expert opinions, thanks in part to initiatives such as Google Books, MIT's release of its educational materials and the open PubMed Central library of the National Library of Medicine. In general, the Internet tends to provide more current coverage than print media, due to the ease with which material on the Internet can be updated. In rapidly changing fields such as science, technology, politics, culture and modern history, the Britannica has struggled to stay up-to-date, a problem first analysed systematically by its former editor Walter Yust. Although the Britannica is now available both in multimedia form and over the Internet, its preeminence is being challenged by other online encyclopaedias, such as Encarta and Wikipedia.

Print encyclopedias

The Encyclopædia Britannica has been compared with other print encyclopaedias, both qualitatively and quantitatively. A well-known comparison is that of Kenneth Kister, who gave a qualitative and quantitative comparison of the Britannica with two comparable encyclopaedias, Collier's Encyclopedia and the Encyclopedia Americana. For the quantitative analysis, ten articles were selected at random (circumcision, Charles Drew, Galileo, Philip Glass, heart disease, IQ, panda bear, sexual harassment, Shroud of Turin and Uzbekistan) and letter grades (A–D, F) were awarded in four categories: coverage, accuracy, clarity, and recency. In all four categories and for all three encyclopaedias, the four average grades fell between B− and B+, chiefly because not one encyclopaedia had an article on sexual harassment in 1994. In the accuracy category, the Britannica received one D and eight As. Encyclopedia Americana received eight As, and Collier's received one D and seven As; thus, Britannica received an average score of 92% for accuracy to Americana’s 95% and Collier's’ 92%. The 1994 Britannica was faulted for publishing an inflammatory story about Charles Drew that had long been discredited. In the timeliness category, Britannica averaged an 86% to Americana’s 90% and Collier's’ 85%. After a more thorough qualitative comparison of all three encyclopedias, Kister recommended Collier's Encyclopedia as the superior encyclopaedia, primarily on the strength of its excellent writing, balanced presentation and easy navigation.

Digital encyclopedias on optical media

The most notable competitor of the Britannica among CD/DVD-ROM digital encyclopedias is Encarta, a modern, multimedia encyclopedia that incorporates three print encyclopedias: Funk and Wagnalls', Collier's and the New Merit Scholar. Encarta is the top-selling multimedia encyclopaedia, based on total U.S. retail sales from January 2000 to February 2006. Both occupy the same price range, with the 2007 Encyclopædia Britannica Ultimate CD or DVD costing US$50 and the Microsoft Encarta Premium 2007 DVD costing US$45. The Britannica contains 100,000 articles and Merriam-Webster's Dictionary and Thesaurus (U.S. only), and offers Primary and Secondary School editions. Encarta contains 66,000 articles, a user-friendly Visual Browser, interactive maps, math, language and homework tools, a U.S. and UK dictionary, and a youth edition. Like Encarta, the Britannica has been criticised for being biased towards United States audiences; the United Kingdom-related articles are updated less often, maps of the United States are more detailed than those of other countries, and it lacks a UK dictionary. Like the Britannica, Encarta is available online by subscription, although some content may be accessed for free.

Internet encyclopedias

Online alternatives to the Britannica include Wikipedia, a freely available Web-based free-content encyclopedia. Wikipedia received roughly 450 times more traffic than the online version of the Britannica in the first three months of 2007, based on Alexa which bases its results on a non-scientific sample of users of its toolbar software.

A key difference between the two encyclopaedias lies in article authorship. The 699 Macropædia articles are generally written by identified contributors, and the roughly 65,000 Micropædia articles are the work of the editorial staff and identified outside consultants. Thus, a Britannica article either has known authorship or a set of possible authors (the editorial staff). With the exception of the editorial staff, most of the Britannica's contributors are experts in their field—some are Nobel laureates. By contrast, the articles of Wikipedia are written by a community of editors with varying levels of expertise: most editors do not claim any particular expertise; of those who do, many are anonymous and have no verifiable credentials. Another difference is the pace of article change: the Britannica is published in print every few years, while Wikipedia's articles are likely to change frequently. Wikipedia has been criticised in other respects as well, and it has been argued that Wikipedia cannot hope to rival the Britannica in accuracy.

On 14 December 2005, the scientific journal Nature reported that, within 42 randomly selected general science articles, there were 162 mistakes in Wikipedia versus 123 in Britannica. In its detailed 20-page rebuttal, Encyclopædia Britannica, Inc. characterized Nature's study as flawed and misleading and called for a "prompt" retraction. It noted that two of the articles in the study were taken from a Britannica year book, and not the encyclopedia; another two were from Compton's Encyclopedia (called the Britannica Student Encyclopedia on the company's web site). The rebuttal went on to mention that some of the articles presented to reviewers were combinations of several articles, and that other articles were merely excerpts but were penalized for factual omissions. The company also noted that several facts classified as errors by Nature were minor spelling variations, and that several of its alleged errors were matters of interpretation. Nature defended its story and declined to retract, stating that, as it was comparing Wikipedia with the web version of Britannica, it used whatever relevant material was available on Britannica's website.

1Supplement to the fourth, fifth, and sixth editions of the Encyclopaedia Britannica. With preliminary dissertations on the history of the sciences.

2 The 8th to 14th editions included a separate index volume.

3 The 9th edition featured articles by notables of the day, such as James Maxwell on electricity and magnetism, and William Thomson (who became Lord Kelvin) on heat.

4 The 10th edition included a maps volume and a cumulative index volume for the 9th and 10th edition volumes: the new volumes, constituting, in combination with the existing volumes of the 9th ed., the 10th ed. … and also supplying a new, distinctive, and independent library of reference dealing with recent events and developments

5Vols. 30–32 … the New volumes constituting, in combination with the twenty-nine volumes of the eleventh edition, the twelfth edition

6 This supplement replaced the previous supplement: The three new supplementary volumes constituting, with the volumes of the latest standard edition, the thirteenth edition.

7 This edition was the first to be kept up to date by continual (usually annual) revision.

8 The 15th edition (introduced as "Britannica 3") was published in three parts: a 10-volume Micropædia (which contained short articles and served as an index), a 19-volume Macropædia, plus the Propædia (see text). It was reorganised in 1985 to have 12 and 17 volumes in the Micro- and Macropædia.

9 In 1985, the system was modified by adding a separate two-volume index; the Macropædia articles were further consolidated into fewer, larger ones (for example, the previously separate articles about the 50 U.S. states were all included into the "United States of America" article), with some medium-length articles moved to the Micropædia.

The first CD-ROM edition was issued in 1994. At that time also an online version was offered for paid subscription. In 1999 this was offered for free, and no revised print versions appeared. The experiment was ended in 2001 and a new printed set was issued in 2002.